1. Field of the Invention
This invention generally relates to apparatus for controlling light transmission by bubbles, and in particular, to a bubble-controlled light transmission apparatus in which transmission of light is controlled by production and disappearance of air bubbles in opaque liquid. Such a bubble-controlled light transmission apparatus may be applied as a light switching device for converting electrical signals into light signals and a display device.
2. Description of the Prior Art
Various types of light transmission control apparatus are used. One typical application of light transmission control apparatus is an optical writing device for optically writing image information on the surface of a photosensitive member in a non-impact type printer. Upon writing, the photosensitive member is subjected to any well-known electrophotographic process to obtain a visual image. Such an optical writing device is usually comprised of a liquid crystal rod or photomagnetic effect element as a means for converting electrical signals into optical signals which are to be used in writing information on a recording medium such as a photosensitive member. However, in such prior art optical write-in devices, the response speed is relatively slow, e.g., approximately 0.5 msec. for the liquid crystal case and 0.015 msec. for the photomagnetic effect element case. Moreover, such prior art devices are complicated in structure and thus difficult to manufacture, thereby increasing manufacturing cost. Therefore, there has been a need to develop a new optical switching device faster in response time and simpler in structure.